From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH] dt: add helper function to read u8 & u16 variables & arrays Date: Tue, 20 Nov 2012 22:24:04 -0600 Message-ID: <50AC5764.7030401@gmail.com> References: <0ee5b74534a09d75c14b22c2d9330c4971ab30fb.1353386646.git.viresh.kumar@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <0ee5b74534a09d75c14b22c2d9330c4971ab30fb.1353386646.git.viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: Viresh Kumar Cc: spear-devel-nkJGhpqTU55BDgjK7y7TUQ@public.gmane.org, linaro-dev-cunTk1MwBs8s++Sfvej+rw@public.gmane.org, andriy.shevchenko-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, patches-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org List-Id: devicetree@vger.kernel.org On 11/19/2012 10:45 PM, Viresh Kumar wrote: > This adds following helper routines: > - of_property_read_u8_array() > - of_property_read_u16_array() > - of_property_read_u8() > - of_property_read_u16() > > This expects arrays from DT to be passed as: > - u8 array: > property = /bits/ 8 <0x50 0x60 0x70>; > - u16 array: > property = /bits/ 16 <0x5000 0x6000 0x7000>; > > Signed-off-by: Viresh Kumar Applied. Rob > --- > V2->V3: > - Expect u8 & u16 arrays to be passed using: /bits/ 8 or 16 > - remove common macro, as not much common now :( > - Tested on ARM platform. > > drivers/of/base.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of.h | 30 +++++++++++++++++++++ > 2 files changed, 107 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index af3b22a..f564e31 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -671,12 +671,89 @@ struct device_node *of_find_node_by_phandle(phandle handle) > EXPORT_SYMBOL(of_find_node_by_phandle); > > /** > + * of_property_read_u8_array - Find and read an array of u8 from a property. > + * > + * @np: device node from which the property value is to be read. > + * @propname: name of the property to be searched. > + * @out_value: pointer to return value, modified only if return value is 0. > + * @sz: number of array elements to read > + * > + * Search for a property in a device node and read 8-bit value(s) from > + * it. Returns 0 on success, -EINVAL if the property does not exist, > + * -ENODATA if property does not have a value, and -EOVERFLOW if the > + * property data isn't large enough. > + * > + * dts entry of array should be like: > + * property = /bits/ 8 <0x50 0x60 0x70>; > + * > + * The out_value is modified only if a valid u8 value can be decoded. > + */ > +int of_property_read_u8_array(const struct device_node *np, > + const char *propname, u8 *out_values, size_t sz) > +{ > + struct property *prop = of_find_property(np, propname, NULL); > + const u8 *val; > + > + if (!prop) > + return -EINVAL; > + if (!prop->value) > + return -ENODATA; > + if ((sz * sizeof(*out_values)) > prop->length) > + return -EOVERFLOW; > + > + val = prop->value; > + while (sz--) > + *out_values++ = *val++; > + return 0; > +} > +EXPORT_SYMBOL_GPL(of_property_read_u8_array); > + > +/** > + * of_property_read_u16_array - Find and read an array of u16 from a property. > + * > + * @np: device node from which the property value is to be read. > + * @propname: name of the property to be searched. > + * @out_value: pointer to return value, modified only if return value is 0. > + * @sz: number of array elements to read > + * > + * Search for a property in a device node and read 16-bit value(s) from > + * it. Returns 0 on success, -EINVAL if the property does not exist, > + * -ENODATA if property does not have a value, and -EOVERFLOW if the > + * property data isn't large enough. > + * > + * dts entry of array should be like: > + * property = /bits/ 16 <0x5000 0x6000 0x7000>; > + * > + * The out_value is modified only if a valid u16 value can be decoded. > + */ > +int of_property_read_u16_array(const struct device_node *np, > + const char *propname, u16 *out_values, size_t sz) > +{ > + struct property *prop = of_find_property(np, propname, NULL); > + const __be16 *val; > + > + if (!prop) > + return -EINVAL; > + if (!prop->value) > + return -ENODATA; > + if ((sz * sizeof(*out_values)) > prop->length) > + return -EOVERFLOW; > + > + val = prop->value; > + while (sz--) > + *out_values++ = be16_to_cpup(val++); > + return 0; > +} > +EXPORT_SYMBOL_GPL(of_property_read_u16_array); > + > +/** > * of_property_read_u32_array - Find and read an array of 32 bit integers > * from a property. > * > * @np: device node from which the property value is to be read. > * @propname: name of the property to be searched. > * @out_value: pointer to return value, modified only if return value is 0. > + * @sz: number of array elements to read > * > * Search for a property in a device node and read 32-bit value(s) from > * it. Returns 0 on success, -EINVAL if the property does not exist, > diff --git a/include/linux/of.h b/include/linux/of.h > index b4e50d5..bfdc130 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -223,6 +223,10 @@ extern struct device_node *of_find_node_with_property( > extern struct property *of_find_property(const struct device_node *np, > const char *name, > int *lenp); > +extern int of_property_read_u8_array(const struct device_node *np, > + const char *propname, u8 *out_values, size_t sz); > +extern int of_property_read_u16_array(const struct device_node *np, > + const char *propname, u16 *out_values, size_t sz); > extern int of_property_read_u32_array(const struct device_node *np, > const char *propname, > u32 *out_values, > @@ -364,6 +368,18 @@ static inline struct device_node *of_find_compatible_node( > return NULL; > } > > +static inline int of_property_read_u8_array(const struct device_node *np, > + const char *propname, u8 *out_values, size_t sz) > +{ > + return -ENOSYS; > +} > + > +static inline int of_property_read_u16_array(const struct device_node *np, > + const char *propname, u16 *out_values, size_t sz) > +{ > + return -ENOSYS; > +} > + > static inline int of_property_read_u32_array(const struct device_node *np, > const char *propname, > u32 *out_values, size_t sz) > @@ -470,6 +486,20 @@ static inline bool of_property_read_bool(const struct device_node *np, > return prop ? true : false; > } > > +static inline int of_property_read_u8(const struct device_node *np, > + const char *propname, > + u8 *out_value) > +{ > + return of_property_read_u8_array(np, propname, out_value, 1); > +} > + > +static inline int of_property_read_u16(const struct device_node *np, > + const char *propname, > + u16 *out_value) > +{ > + return of_property_read_u16_array(np, propname, out_value, 1); > +} > + > static inline int of_property_read_u32(const struct device_node *np, > const char *propname, > u32 *out_value) >